DEMs by Sonny

Do you know this site: https://sonny.4lima.de/? It’s a brilliant resource for DEMs for most European countries and beyond. Why? Because at the intermediate spatial resolution of 20 to 90 m, we are usually stuck with SRTM, ALOS 3D World, Aster GDEM, etc. But these DEMs have their drawbacks. They are affected by vegetation and buildings and may have other artefacts related to their acquisition technique. The gold standard in DEM acquisition is LiDAR. But downloading LiDAR DEMs with a resolution of 1-2 m can be tough if the area of interest is large. Download volume may easily comprise 100s of Gb. And since you will hardly be able to process this data, you will most likely downsample the data to a coarser resolution.

Now this is where Sonny’s DEM site comes in. It contains tons of LiDAR DEMs resampled to spatial resolutions at which we can work at the regional, national and continental scale. I tried it for a 20 m DEM of Svalbard. To plot the data, I set 0-values to nan and then calculated a hillshaded image using imageschs. Here are the results:

Sonny has invested an incredible effort to produce these DEMs. The site contains the result of hundreds to thousands of hours computing time next to many, many hours of downloading, organizing and checking the data. Thanks for providing this resource to the community, Sonny.